1. Field of Invention
This invention pertains to in situ determination of copper (I) in an aqueous medium containing copper (I).
2. Description of Prior Art
Ship bottoms, buoys, fishing nets, and other structures submerged in seawater such as cooling water intake or discharge pipes are infested with marine organisms such as barnacles, tube worms and algae that attach to the surface of these structures and cause various problems. It is routine practice to prevent the attachment of these marine fouling organisms by coating the surfaces of the aforementioned items with antifouling paints or coatings.
With the restrictions on the use of toxic coatings in many countries, the boat and ship owners have been using copper oxide-based coatings. The effective life of copper oxide-based coatings on ship or boat hulls rarely exceeds 5 years if the hulls are not mechanically scrubbed or frequently repainted to limit the effect of marine organisms on fuel consumption and speed of the ship or boat so that drag is held to a minimum tolerable quantity. Therefore, a major source of copper in the marine environment is from antifouling paints on boat and ship hulls.
The copper-containing antifouling paint on hulls of boats or ships prevents some and reduces other marine organisms from attaching to the hulls. With organism attachment to a hull comes increased drag and thus increased fuel consumption during passage through water. In addition, organism fouling clogs intakes and reduces pipe diameters.
With the requirement to reduce or eliminate environmental contamination, there is a problem with copper (I) levels leached from hulls of boats and ships in port as well as the fines and disposal costs developed during grinding and repainting of the hull.
Furthermore, effectiveness of a copper-containing antifouling paint is tied to leaching of copper (I) ions into the water in which the hull is disposed. When leaching of the copper (I) stops, effectiveness of the paint ceases since leaching of the ionic copper into water is relied upon to kill marine organisms already attached to the hull or to dissuade the marine organisms from settling on the hull. So, in order to determine effectiveness of the paint, boat and ship owners want to know if the paint is leaching copper (I) since copper (I) leaches from a copper-containing antifouling paint.
It is an object of this invention to determine concentration of copper (I) in water to the level of about 5 ppb.
It is another object of this invention to determine copper (I) concentration by an in situ approach quickly in less than one half hour.
It is another object of this invention to determine copper (I) concentration in seawater by a robust technique which does not require the use of a spectrophotometer or require any special training.
It is another object of this invention to determine if a copper-containing antifouling paint continues to release copper (I) in water.
These and other objects of this invention are attained by a probe which measures concentration of ionic copper (I) by changing color in response to the quantity of ionic copper present in the water. The probe includes a substrate and a BCP compound thereon, the color of which probe is compared to a standard in order to determine concentration of the ionic copper in the water.